There’s been some anxiety expressed about an apparent recent dip in support for the SNP shown in the last 4 sub-polls.

Opinium/Observer had them at 38% for 3-4 October. YouGov/Times had them at 35% for 30 September to 1 October. YouGov/Sunday Times had them at 38% for 24-25 September. Opinium/Observer had them at 37% for 25-27 September.

At first sight it seems like evidence of a fairly real fall from solid >40% figures for most of this year. However, unusually, Opinium did not tell us what the results would be with the don’t knows removed but we can easily produce those. With that done, the SNP score would be above 40% in both. I make it 43.33% (52 out of 120) for 3-4 October and 46.7% (51 out of 109) for 25-27 September.

Given the unreliability of sub-polls we need to average a group to get any kind of picture. Doing that we get 40.7%. in the period 24 September to 4 October and thus no significant change.